Many security approaches, for example parcel and passenger screening at airports, utilize devices configured to detect trace amounts of explosive material. However, there are thousands of explosive compounds that may be utilized in a malicious manner, and no single approach is capable of detecting every such compound. Additionally, various explosive precursors may not be detectable by a particular device configured to detect the final explosive compounds.
Moreover, certain existing sensors, for example nanotube sensors utilizing titanium dioxide nanotubes, can suffer degradation of performance or become inoperable under certain common operating conditions, for example when exposed to moisture and/or saline vapor. Accordingly, improved nanotube sensors remain desirable, particularly in connection with detection of explosive compounds or other molecules of interest.